No,
Physically, the connector (RJ45) looks the same but electrically, it's very different. If you put any CAT 5 or CAT 5E (enhanced CAT 5) into a CAT 6 system, the performance will drop and you'll get nothing but problems. At this point in time, you can't even mix and match CAT 6 componants from various vendors!! In some cases the same vendor will have two or more CAT 6 solutions that are not compatible!!!! So if you need to replace a CAT 6 wall plate, verify the vendor and the model number and order the exact item or a suitable replacement.
hope this helps!